This invention relates to a method and apparatus for removing fiber tufts from the top of textile fiber bales such as cotton bales, chemical fiber bales or the like, in which an opening device is moved back and forth above the top face of the serially arranged fiber bales and in which the opening device is incrementally lowered prior to the beginning of each pass. The opening device has an opening roll provided with teeth which are unidirectionally obliquely oriented and engage into the top face of the fiber bales as they project downwardly between generally horizontally oriented grate bars.
In a known process in which the teeth of the opening roll are obliquely oriented in the same direction, the opening device executes a working pass (that is, a pass during which fiber tufts are removed) only in one direction of travel, in which the opening roll is so rotated that in the working zone it moves opposite to the direction of travel. Such a direction of travel of the opening device will be referred to as forward travel (or pass in the forward direction). Subsequently, the opening device is moved in an idling state above the fiber bales in the reverse direction, and thereafter, it is lowered deeper than at the preceding pass and starts a new working pass in the forward direction. It is disadvantage of this arrangement that the fiber output of the bale opener is limited, since no fiber tufts are removed during the reverse pass.